Wyniki wyszukiwania - BazTech

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A novel device with variable friction for shock and vibration control

Sireteanu T., Mitu A. -M., Ghitau G., Niculescu A., Jankowski A., Kowalski M.

Journal of KONES

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2017

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Vol. 24, No. 3

261--268

EN

In this article a passive system, which exploits the properties of the Coulomb friction and leads to high affordability of controlling shocks and vibrations by means of cheap devices is presented. The friction force developed by the proposed device is dependent on the motion stroke by convenient modulation of contact force between the elements of friction coupling. For providing the system self-centring properties or necessary vertical load capacity, coil springs can be incorporated into the device structure. The device hysteresis characteristic can be simply adjusted to comply with requirements of the considered application. A general mathematical model of device dynamic behaviour is developed and applied to shock and vibration isolation systems. The article presents a novel passive device with variable friction which hysteresis force-displacement characteristics have “butterfly” shape, achieved by appropriate design of friction coupling. This shape of hysteresis loops can mitigate the drawbacks of constant friction devices. The schematic of mechanical systems to analyse the dynamic behaviour of shock and vibration isolation systems with variable friction device are shown.

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Some results obtained from three dimensional plate kinematics analyses in Romania - (1997-2000)

Ghitau G.

Reports on Geodesy

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2006

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z. 4/79

103-115

EN

Within CERGOP-2/ENVIRONMENT project, a special attention is given to geodynamics models development for specific regions from countries that participate to the present project. For this goal, study groups were created (WPs-1O.x) which has the main objectives to monitor recent crust movements, to detect the borders of the tectonic plates and to quantify their three dimensional movement rates.

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National progress report of Romania

Ghitau G., Gavrilescu M., Nacu V., Dumitrascu D., Nastase F., Mateiciuc D.

Reports on Geodesy

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2006

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z. 4/79

99-102

EN

Starting with year 2001 over Romania's territory there have been installed 5 Permanent GPS Stations in municipalities of SUCEAVA, CLUJ, TIMISOARA, SIBIU and BRAILA. As it is already known, a few years ago, BKG has donated to the University of Constructions in Bucharest a Permanent GPS Station which is functioning perfectly, in real time and with no delays. From administration reasons, and not only, there was impossible, yet, to unite the Permanent GPS Stations mentioned above, within a network that may function at adequate parameters. At the present, the records effected at the first 5 stations are periodically transmitted on CD-s, to a Processing and Control Center which is functioning within the Institute of Cadastre, Geodesy, Photogrammetry and Cartography. This one is acting at present only as data collector. We are about to create the Network of Permanent GPS Stations for Romania. We have to consider this development trend, for the future.